Semiconductor devices are used in a variety of electronic applications, such as, for example, personal computers, cell phones, digital cameras, and other electronic equipment. Semiconductor devices are typically fabricated by sequentially depositing insulating or dielectric layers, conductive layers, and semiconductor layers of material over a semiconductor substrate, and patterning the various material layers using lithography to form circuit components and elements thereon.
The semiconductor industry continues to improve the integration density of various electronic components (e.g., transistors, diodes, resistors, capacitors, etc.) by continual reductions in minimum feature size, which allow more components to be integrated into a given area. Concurrently, conductive structures, such as, for example, contact plugs, that provide an electrical connection to and/or from the various electronic components have also experienced continual reductions in critical dimensions and minimum feature size. However, these reductions in critical dimensions and minimum feature size are often accompanied by an increase in contact resistance of the conductive structures.